Endre søk
Begrens søket
2345678 201 - 250 of 613
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Disputationsdatum (tidligste først)
  • Disputationsdatum (siste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 201. Hinger, Gunnar
    et al.
    Brinkmann, Markus
    Bluhm, Kerstin
    Sagner, Anne
    Takner [Olsman], Helena
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Eisentraeger, Adolf
    Braunbeck, Thomas
    Engwall, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Tiehm, Andreas
    Hollert, Henner
    Some heterocyclic aromatic compounds are Ah receptor agonists in the DR-CALUX assay and the EROD assay with RTL-W1 cells2011Inngår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 18, nr 8, s. 1297-1304Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose Heterocyclic aromatic compounds containing nitrogen, sulfur, or oxygen heteroatoms (NSO-HET) have been detected in air, soil, marine, and freshwater systems. However, only few publications are available investigating NSO-HET using in vitro bioassays. To support better characterization of environmental samples, selected NSO-HET were screened for dioxin-like activity in two bioassays. Methods The present study focuses on the identification and quantification of dioxin-like effects of 12 NSO-HET using the DR-CALUX assay, and the 7-ethoxyresorufin-O-deethylase (EROD) assay with the permanent fish liver cell line RTL-W1. Changes of the total medium compound concentrations during the test procedure due to, e.g., sorption or volatilization were quantified using GC/MS. Results The NSO-HET benzofuran, 2,3-dimethylbenzofuran, dibenzofuran, dibenzothiophen, acridine, xanthene, and carbazole caused a response in the DR-CALUX assay. Only benzofuran and 2,3-dimethylbenzofuran were also positive in the EROD assay. All other compounds were inactive in the EROD assay. Relative potency (REP) values ranged from (2.80 +/- 1.32) center dot 10(-8) to (3.26 A +/- 2.03) A center dot 10(-6) in the DR-CALUX and from (3.26 A +/- 0.91) A center dot 10(-7) to (4.87 A +/- 1.97) A center dot 10(-7) in the EROD assay. Conclusions The REP values were comparable to those of larger polycyclic aromatic hydrocarbons, e.g., fluoranthene and pyrene. Thus, and because of the ubiquitous distribution of heterocyclic aromatic compounds in the environment, the provided data will further facilitate the bioanalytical and analytical characterization of environmental samples towards these toxicants.

  • 202. Hollert, Henner
    et al.
    Keiter, Steffen
    Böttcher, Melanie
    Grund, Steffi
    Seitz, Nadja
    Otte, Jens
    Bluhm, Kerstin
    Wurm, Karl
    Hecker, Markus
    Higley, Eric
    Giesy, John
    Takner [Olsman], Helena
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engwall, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Reifferscheid, Georg
    Manz, Werner
    Erdinger, Lother
    Schulze, Tobias
    Luebcke-van Varel, Urte
    Kammann, Ulrike
    Schöneberger, René
    Suter, Marc
    Brack, Werner
    Strähle, Uwe
    Braunbeck, Thomas
    Eine Weight-of-Evidence-Studie zur Bewertung der Sedimentbelastung und des Fischrückgangs in der Oberen Donau [Assessing sediments and fish health using a weight-of-evidence approach : in search for the causes of fish decline in the Danube river]2009Inngår i: Umweltwissenschaften und Schadstoff-Forschung, ISSN 0934-3504, E-ISSN 1865-5084, Vol. 21, nr 3, s. 260-263Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and aim Despite intensive and continuous stocking and improvement of water quality since the 1970s, fish populations, especially those of the grayling (Thymallus thymallus), have declined over the last two decades in the upper Danube River (Germany). In order to assess 1) possible links between molecular/biochemical responses and ecologically relevant effects, and 2) if ecotoxicological effects might be related to the decline in fish catches in the upper Danube river, sediment samples and fish were collected at different locations and analyzed using a weight-of-evidence (WOE) approach with several lines of evidence. The objective of the presentation is to introduce the conceptual framework and to review results of the ongoing study. As previously addressed by Chapman and Hollert (2006) a variety of lines of evidence can be used in WOE studies. Briefly, 1) a comprehensive battery of acute and mechanism-specific bioassays was used to characterize the ecotoxicological hazard potential. 2) Histopathological investigations and the micronucleus assay with erythrocytes were applied, analyzing in situ parameters. 3) Diversity and abundance of benthic macroinvertebrates and fish as well as 4) persistent organic pollutants, endocrine disrupting substances, limnochemical parameters and the concentration of heavy metals were recorded. To identify organic contaminants a spotential causes of sediment toxicity assays, 5) effect directed analysis was applied. © 2009 Springer-Verlag.

  • 203.
    Holmberg, Thom
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lindberg, Martin
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lindberg, Oskar
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Automatisering av paketeringsprocess2010Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Examensarbetet syftar till att undersöka om automatisering av den manuella paketeringsprocessen på Legosan AB vore lönsam. Legosan AB, beläget i Kumla, legotillverkar kosttillskott och läkemedel till företag inom Europa. Kapitlet Nulägesanalys beskriver hur tillverkningen och paketeringsprocessen fungerar i dagsläget och syftar till att ge en tydlig bild av processer, layouter och materialflöden. Detta beskrivs med hjälp av layoutskisser, processkartläggningar och en frekvensstudie. Nulägesanalysen avslutas med en kravspecifikation. I kapitlet Förbättringsförslag presenteras två olika förslag i två olika utföranden som beskrivs bland annat genom layoutskisser och processbeskrivningar. Dessutom beskrivs investeringar och åtgärder för respektive förslag. I det första förbättringsförslaget används en fyraxlig palleteringsrobot medan det i det andra förslaget används en kartesisk portalrobot för palleteringen. Eftersom det finns flera olika alternativ i valet av paketeringsroboten är förbättringsförslagen uppdelade i två varianter. Övriga maskiner och utrustning som krävs i förslagen beskrivs även och dess dimensioner redovisas. Avsnittet avslutas med en problemdiskussion. Investeringsanalysen visar vilka kostnader som uppkommer vid en implementering av förbättringsförslagen. Dessutom beräknas pay-offtider och en kapitalvärdekalkyl redovisas. I kapitlet Slutsatser och Rekommendationer diskuteras för och nackdelar med de olika förbättringsförslagen. Därefter rekommenderas en lösning.

  • 204.
    Holmberg, Thom
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Linderg, Oskar
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lindberg, Martin
    Örebro universitet, Akademin för naturvetenskap och teknik.
    AUTOMATISERING AV PAKETERINGSPROCESS2010Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [en]

    The aim of this thesis is to investigate if an automation of the manual packaging process at Legosan AB is profitable. Legosan AB, located in Kumla, performs subcontract work of dietary supplements and medical products to companies within Europe. The chapter

    portal robot is used in the other. As there are several options in the choice of packaging robot the suggestions of improvement are divided into two different designs. Other machines and equipment necessary for the different suggestions of improvement are showed and their measurements are presented. The chapter ends with a problem discussion.

    Nulägesanalys describes how the manufacturing process and the packaging process operates today and aims to give a good understanding of the processes, layouts and material flows. This is showed through layout sketches, process mapping and a frequency study. The chapter ends with a specification of requirements. In the chapter Förbättringsförslag two different suggestions of improvement is presented in two different designs that is present by layout sketches and process descriptions. Also the investments and measures are described in the different suggestions. In the first suggestion a four-axis pallet robot is used while a kartesian iii The analysis of investments shows the costs that appear due to the implementation of the suggestions of improvement. In addition pay-off time is calculated and a capitalization calculation is shown. In the chapter Slutsatser och Rekommendationer pros and cons for the different suggestions are discussed. Finally a solution is recommended.

  • 205.
    Holmstrom, S. J. M.
    et al.
    Mid Sweden Univ, Dept Nat Sci Engn & Math, S-85170 Sundsvall, Sweden.
    Rosling, A.
    Swedish Univ Agr Sci, Dept Forest Mycol & Pathol, S-75007 Uppsala, Sweden.
    Finlay, R. D.
    Swedish Univ Agr Sci, Dept Forest Mycol & Pathol, S-75007 Uppsala, Sweden.
    van Hees, Patrick A. W.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Lundstrom, U. S.
    Mid Sweden Univ, Dept Nat Sci Engn & Math, S-85170 Sundsvall, Sweden.
    Contribution of ectomycorrhizal fungi to biogeochemical processes during iron and calcium limitation2009Inngår i: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 73, nr 13, s. A546-A546Artikkel i tidsskrift (Annet vitenskapelig)
  • 206. Horii, Yuichi
    et al.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kannan, Kurunthachalam
    Petrick, Gert
    Nachtigall, Kerstin
    Yamashita, Nobuyoshi
    Novel evidence for natural formation of dioxins in ball clay2008Inngår i: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 70, nr 7, s. 1280-1289Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Elevated concentrations of dioxins in ancient ball clay from the Mississippi Embayment suggest natural formation of dioxins in the environment. Evidence for such natural formation in ball clay derives from unique congener profiles in undisturbed ancient clay deposits and from the lack of other anthropogenic contaminants. Here we present novel evidence of natural formation of dioxins based on congener-specific carbon isotopic analysis of octachlorodibenzo-p-dioxin (OCDD) in ball clays from the USA and Japan. The analyses were performed using a combination of double-column high performance liquid chromatography clean-up and two-dimensional gas chromatography-isotope ratio mass spectrometry. Elevated concentrations of OCDD found in ball clays from the USA and Japan were isotopically distinguished from the anthropogenic source materials (fly ash and pentachlorophenol) and environmental samples (sediment and soil). The isotopic signatures and the occurrence of OCDD in ancient ball clays deposited in the Tertiary Era provide evidence for the in situ formation of dioxins.

  • 207. Hossain, Mohammad Sorowar
    et al.
    Larsson, Anders
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Scherbak, Nikolai
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Olsson, Per-Erik
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Orban, Laszlo
    Zebrafish androgen receptor: isolation, molecular, and biochemical characterization2008Inngår i: Biology of Reproduction, ISSN 0006-3363, E-ISSN 1529-7268, Vol. 78, nr 2, s. 361-369Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Androgens play an important role in male sexual differentiation and development. They exert their function by binding to and activating the androgen receptor (Ar), a member of the steroid hormone receptor superfamily. Here, we report on the isolation and characterization of zebrafish Ar. The complete transcript of zebrafish ar is 5.3 kb long encoding a putative polypeptide of 868 amino acids. Our experimental and bioinformatic analysis has found a single ar locus in zebrafish. Phylogenetic analysis using the ligand-binding domain showed that the zebrafish Ar clustered with its cyprinid orthologs to form a separate group, which was closer to the beta clade than to the alpha clade. Tissue-specific expression analysis revealed that the ar mRNA was expressed ubiquitously in all adult tissues tested, with sexually dimorphic expression in the gonad and muscle. While the ar transcript was maternally deposited into the embryo, signs of zygotic expression could be detected as early as 24 h after fertilization, and the expression level increased substantially afterwards. When analyzed during gonad development, the expression level of ar mRNA at 4 wk after fertilization was similar in both developing gonads but later became higher in the transforming testis, suggesting a potential role during male gonad differentiation. We also combined theoretical modeling with in vitro experiments to show that the zebrafish Ar is preferentially activated by 11-ketotestosterone.

  • 208.
    Härlin Lennermark, Mikael
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Modeling of experimental studies of fluid and particle transport in porous media2009Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    To extract metals and increase the pH value of water around a historical mine waste deposit a series of barrels are used. Polluted water is forced to pass inside these barrels where different filter materials purify the water. This research project is carried out in Sweden by MTM at Örebro University and Bergkraft in Kopparberg, titled “Methods for characterisation and remediation of historical mine waste”.

     

    The fluid flow trough the filter materials in the barrels are needed to be understood, in order to improve the extracting process.

     

    In this work a small transparent model filled with sand was made to visualise the fluid flow. In that model coloured water is representing the polluted water. To describe the flow in the transparent model a mathematical model is presented. The theory used in this work is the complex variable method in fluid dynamics together with numerical methods and computer programming. There is a pretty good match between the theoretical and experimental results presented in two dimensions. Continuing work could result in a three dimensional model with different geometries using the same technique.

  • 209.
    Höglund Aldrin, Ronja
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Hur bildas svarta hål?: Neutronstjärnor, kaonkondensation och dess konsekvenser och Minihål på jorden?2008Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Med utgångspunkt från den teoretiska bakgrunden, definitionen av svarta hål och deras generella egenskaper har jag studerat villkor för bildandet av svarta hål från döende singulära stjärnor. Supernovaprocessen beskrivs tillsammans med hur neutronstjärnor kan påverkas av destabiliserande mekanismer som t.ex. kaonkondensation. Olika observationer samt alternativa teorier läggs fram som argument och motargument. Utifrån detta underlag drar jag slutsatsen att svarta hål kan existera i fler varianter än vad som hittills antagits, främst i form av s.k. lågmassiva svarta hål på 1,5-1,8 Msol.

     

    Vidare skildras möjligheten att producera mikroskopiska svarta hål i LHC-acceleratorn (Large Hadron Collider) i CERN, de kontroverser som omgärdar detta fenomen och de kunskaper som skulle kunna vinnas från kontrollerade observationer av sådana objekt. Den generella slutsatsen här är det ofrånkomliga mötet mellan partikelfysik och astrofysik för att få tillgång till de allra djupaste insikterna om det universum vi lever i.

  • 210.
    Höglund Aldrin, Ronja
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Svarta hål i Vintergatan: Mörk materia, gravitationslinser och MACHOs2009Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    Ett av de mest notoriska dilemman i dagens kosmologi är den mörka materians natur och dess förekomst i universum. Mot bakgrund av detta har nya forskningsdiscipliner med rötterna i Einsteins relativitetsteori växt fram, bl.a. teorin om gravitationslinser som möjliggör en indirekt observationsmetod av ljussvaga kompakta objekt som annars skulle vara mycket svåra eller omöjliga att upptäcka på traditionella vis, såsom svarta hål.

    Via en genomgång av grundteorin för gravitationslinser, några enkla teoretiska studier och en grundläggande felmarginalsanalys illustreras hur olika typer av kompakta objekt i Vintergatans omedelbara omgivning kan ge upphov till vissa karakteristiska linsfenomen. Detta sätts i relation till rådande teorier om den tidigaste stjärnbildningen och de massiva kompakta rester som denna generation av mycket massiva stjärnor bör ha efterlämnat – i synnerhet intermediära svarta hål med massor på 100-1000 Msol som ännu kan finnas i dagens mörka galaxhalor. Sådana objekt kan komma att upptäckas i betydligt högre grad i framtiden med de observationstekniker som är under utveckling idag. 

  • 211.
    Jakobsson, David
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    König, Bettina
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Kvalitetsregister för epikutantestning2010Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Inledning: Epikutantester används för utredning av kontaktallergier. Det görs ca 3000 tester varje år i Sverige som överförs till ett kvalitetsregister.  Målet med projektet var att utveckla en webbapplikation och en underliggande databas för hantering och lagring av ett nationellt kvalitetsregister för epikutantester (The Swedish Patch Register). Databasen skall lagras på en central server lokaliserad på Universitetssjukhuset, Örebro.

    Metoder: Lösningen blev en applikation för webbläsare programmerad i språket C# med hjälp av Microsoft Visual Studio 2008 och ramverket ASP.NET 3.5. MySQL .NET connector tool 6.2.2 möjliggjorde anslutningen mellan ASP.NET och databasen. Databasen skapades på MySQL Server 5.1, en databasserver med öppen källkod. Driftsättning av webbapplikationen testades med IIS 7.

    Resultat: En webbapplikation, med en design liknande Örebro Läns Landsting webbplats och med följande funktionalitet skapades: Säker inloggning (https, SSL-certifikat), registrera testresultat, hantera användarkonton och behörigheter, skapa standardtester och lägga till nya ämnen för allergitestning, och en hjälpsida. Inmatningen av data standardiserades genom användning av kalenderkomponenten och DropDownLists med förvalda svar för testreaktioner, bedömning, relevans och ett fördefinierat standardtestsystem, för att minska antalet möjliga felkällor. Databasen inkluderar åtta tabeller och informationen har företrädesvis lagrats som heltalsvärden för att förenkla framtida statistiska beräkningar.

    Diskussion: I brist på licens för Microsoft SQL Server 2008 utvecklades projektet med hjälp av en lösning med öppen källkod som fungerar bra i utvecklingsmiljön. En lösning kopplad till en Microsoft SQL Server 2008 kräver en viss anpassning av källkoden.

  • 212.
    Jakobsson, Patrik
    Örebro universitet, Akademin för naturvetenskap och teknik.
    WEBBAPPLIKATIONER: En praktisk tillämpning för ammunitionsindustrin2009Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Denna rapport behandlar utvecklingen av en webbapplikation åt Gyttorp Cartridge Company med syftet att underlätta, effektivisera och skapa nya möjligheter att hantera produktionstekniska data. Gyttorp Cartridge Company är tillverkare av sport- och jaktammunition. Uppdragsgivarens huvudsakliga krav var att skapa en applikation med samma arbetsgång som det tidigare tillvägagångssättet. Ett problem som löstes var möjligheten för användarna att jobba med gemensamma data. Målet var att lösa problemen på ett kostnadseffektivt och plattformsoberoende sätt och att kunna leverera en väl testad, stabil och användarvänlig lösning.

    Rapporten redogör för ett antal lämpliga metoder som ska ingå i applikationen för att tillgodose uppdragsgivarens krav. Här redogörs behovet av en klient/server-lösning och därav valet av programvaror (LAMP) för applikationen. En webbapplikation valdes som lösning och vidare beskrivs behovet av händelsehantering med asynkron kommunikation.

    För att förenkla programmeringen skrevs ett bibliotek för att hantera händelseanrop och skapa grafiska widgets. Ett tillägg till biblioteket skrevs för att hantera dialogrutor, varningar och felmeddelanden. Med tanke på uppdragets mål på användarvänlighet behandlar rapporten interaktionen mellan dator och människa. Applikationen är användarbaserad och ger möjlighet att anpassa vyer efter användare. Applikationen ger även möjligheten att generera rapporter åt den produktionsansvarige.

    Projektet visade att applikationen underlättar arbetet för arbetsgivaren. Den minskar risken för fel under produktionen. Den uppfyller de krav som ställts och ger även möjligheter för vidare utbyggnad.

    I slutdiskussionen behandlas alternativa vägar för byggande av webbapplikationer. Tillkortakommanden av det egna programbiblioteket tas upp samt hur det kan förbättras. Förslag på hur applikationen kan utökas för att ge ett större värde åt uppdragsgivaren ges.

  • 213.
    Jansson, Chris
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Automatiskt bygge av FUS39A2011Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    This paper describes the design and implementation of an automated build system for the JAS39A simulator FUS39A at HiQ:s offices in Arboga. The assignment was to automate the process in which modules are built; the simulator is composed of a number of modules which are built manually at the end of each week, this process takes about a day of manual labor. The system can automatically build a module as either a scheduled service or by manual invocation. The system contains functionality for reporting the build results to any given recipient by e-mail. The purpose of the system is to free up the time put into manually building the modules for better suited tasks by automating the build of FUS39A.

    The assignment was split into two parts, an analysis part where information of the old system was gathered, tools and methods were chosen and the new system was designed. In the second part the system was implemented and tested.

  • 214. Jarikote, Dilip V.
    et al.
    Li, Wei
    Jiang, Tao
    Eriksson, Leif A.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Murphy, Paul V.
    Towards echinomycin mimetics by grafting quinoxaline residues on glycophane scaffolds2011Inngår i: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, E-ISSN 1464-3391, Vol. 19, nr 2, s. 826-835Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Echinomycin is a natural depsipeptide, which is a bisintercalator, inserting quinoxaline units preferentially adjacent to CG base pairs of DNA. Herein the design and synthesis of echinomycin mimetics based on grafting of two quinoxaline residues onto a macrocyclic scaffold (glycophane) is addressed. Binding of the compounds to calf-thymus DNA was studied using UV-vis and steady state fluorescence spectroscopy, as well as thermal denaturation. An interesting observation was enhancement of fluorescence emission for the peptidomimetics on binding to DNA, which contrasted with observations for echinomycin. Molecular dynamics simulations were exploited to explore in more detail if bis-intercalation to DNA was possible for one of the glycophanes. Bis-intercalating echinomycin complexes with DNA were found to be stable during 20 ns simulations at 298 K. However, the MD simulations of a glycophane complexed with a DNA octamer displayed very different behaviour to echinomycin and its quinoxaline units were found to rapidly migrate out from the intercalation site. Release of bis-intercalation strain occurred with only one of the quinoxaline chromophores remaining intercalated throughout the simulation. The distance between the quinoxaline residues in the glycophane at the end of the MD simulation was 7.3-7.5 angstrom, whereas in echinomycin, the distance between the residues was similar to 11 angstrom, suggesting that longer glycophane scaffolds would be required to generate bis-intercalating echinomycin mimetics. (C) 2010 Elsevier Ltd. All rights reserved.

  • 215.
    Jass, Jana
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Reid, Gregor
    Effect of cranberry drink on bacterial adhesion in vitro and vaginal microbiota in healthy females2009Inngår i: Canadian journal of urology, ISSN 1195-9479, Vol. 16, nr 6, s. 4901-4907Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Introduction/objective: Cranberries have been shown to produce urinary metabolites that influence uropathogen adhesion and prevent urinary tract infections. This study was designed to determine if consuming reconstituted, unsweetened cranberry drink from extract retained its bioactive properties by reducing uropathogen adhesion without adversely affecting urinary calcium, magnesium and the vaginal microflora. Materials and methods: A randomized crossover study Was undertaken in 12 healthy Women consuming reconstituted unsweetened cranberry drink, CranActin or Water. The urine was collected at 4 hours and 1 week of consumption and evaluated for antiadhesive properties and urinary pH, calcium and magnesium. Vaginal swabs Were collected after 1 Week of treatment to assess the vaginal microbiota by DGGE. Results: The resultant urine produced by subjects who consumed 500 ml reconstituted cranberry extract twice per day, significantly reduced the adherence to epithelial cells of P-fimbriated uropathogenic Escherichia coli and showed a tendency towards significance for two E. coli strains expressing fimbriae and an Enterococcus faecalis isolate. The cranberry drink treatment did not alter urinary pH, but reduced calcium and magnesium concentrations compared to Water, although not to statistical significance. The reconstituted cranberry drink may retain the ability to effect on the vaginal microbiota. However, consuming twice daily resulted in an apparent loss of a potential pathogen from the vagina in 42% subjects. Conclusions: The present findings suggest that reconstituted cranberry drink may retain the ability to reduce the risk of UTI by inhibiting pathogen adhesion While not detrimentally affecting urinary pH or vaginal microbiota, or the risk of calculi.

  • 216.
    Jass, Jana
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Schedin, Staffan
    Fällman, Erik
    Ohlsson, Jörgen
    Nilsson, Ulf J.
    Uhlin, Bernt Eric
    Axner, Ove
    Physical properties of Escherichia coli P pili measured by optical tweezers2004Inngår i: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 87, nr 6, s. 4271-4283Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mechanical behavior of individual P pili of uropathogenic Escherichia coli has been investigated using optical tweezers. P pili, whose main part constitutes the PapA rod, composed of approximately 10(3) PapA subunits in a helical arrangement, are distributed over the bacterial surface and mediate adhesion to host cells. They are particularly important in the pathogenesis of E. coli colonizing the upper urinary tract and kidneys. A biological model system has been established for in situ measurements of the forces that occur during mechanical stretching of pili. A mathematical model of the force-versus-elongation behavior of an individual pilus has been developed. Three elongation regions of pili were identified. In region I, P pili stretch elastically, up to a relative elongation of 16 +/- 3%. The product of elasticity modulus and area of a P pilus, EA, was assessed to 154 +/- 20 pN (n=6). In region II, the quaternary structure of the PapA rod unfolds under a constant force of 27 +/- 2 pN (n approximately 100) by a sequential breaking of the interactions between adjacent layers of PapA subunits. This unfolding can elongate the pilus up to 7 +/- 2 times. In region III, pili elongate in a nonlinear manner as a result of stretching until the bond ruptures.

  • 217.
    Jensen, P. E.
    et al.
    Danmarks Tekniske Universitet, Copenhagen, Denmark.
    Ottosen, I. M,.
    Danmarks Tekniske Universitet, Copenhagen, Denmark.
    Allard, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Remediation of soil sludge contaminated by As, Cd, Cr, Cu, Ni, Pb and Zn2011Konferansepaper (Fagfellevurdert)
  • 218.
    Johansson, Andreas
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Dahlbäck, Peter
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Mobil trygghetsapplikation för operativsystemet  Android2010Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    This report details the development of an application for personal safety for the Android operating system. Android is a relatively new platform, primarily used on mobile phones.

    The purpose of the developed application is to give the user the possibility to easily and quickly alert a number of contacts by phone in case of emergencies, and to show the user’s location on a map. This is not only used during emergencies, but for other purposes as well – for example to monitor a jogging round.

    The project was carried out in co-operation with the company D-Safety, the developer of the "SoftAlarm" – the product on which the developed application is based.

  • 219.
    Johansson, Daniel
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    de Vin, Leo J.
    Centre for Intelligent Automation, University of Skövde, Sweden.
    Design and development of an augmented environment with high user mobility for training purposes2008Inngår i: Proceedings of the 11th Mechatronics Forum Biennial International Conference: 23 – 25 June2008, Universith of Limerick, Ireland / [ed] Toal D., Limerick: University of Limerick , 2008Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The paper describes the design and development of a novel cost effective simulator for training of situation awareness, strategy and co-operation. By mixing real and virtual realities in combination with wireless and body-mounted hardware, the result is an augmented environment that allows for high physical mobility against a relatively low cost.

  • 220.
    Johansson, Daniel
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    de Vin, Leo J.
    Centre for Intelligent Automation University of Skövde, Skövde, Sweden.
    Omnidirectional robotic telepresence through augmented virtuality for increased situation awareness in hazardous environments2009Inngår i: Proceedings 2009 IEEE International Conference on  Systems, Man and Cybernetics, IEEE conference proceedings, 2009, s. 6-11Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    This paper proposes a novel low-cost robotic telepresence approach to situation awareness, initially aimed for hazardous environments. The robot supports omnidirectional movement, wide field of vision, haptic feedback and binaural sound. It is controlled through an augmented virtuality environment with an intuitive position displacement scheme that supports physical mobility. The operator thereby can conduct work away from danger whilst retaining situation awareness of the real environment.

  • 221.
    Johansson, Emma M.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Impact of root and mycorrhizal exudation on soil carbon fluxes: influence of elevated CO2 and metals2009Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The thesis concerns the behavior of root and ectomycorrhizal (ECM) exudates. In particular, the dynamics of soluble low molecular weight (LMW) organic compounds such as organic acids (LMWOAs), amino acids, monosaccharides, and dissolved organic carbon (DOC) have been studied. Our knowledge of exudation rates for tree roots and especially associated ECM is limited, and also factors influencing exudation rates. Two environmental factors, metal stress and elevated atmospheric CO2 level, have been investigated. Both are of great environmental concern, but function in different ways (detoxification and C allocation) and may be highly important for the C flux caused by root/ECM exudation. The project has been carried out with mycorrhizal and nonmycorrhizal (NM) Scots pine seedlings, or saprotrophic fungi, under both sterile and non-sterile (soil) conditions. Analytical determination of exudates and calculation of exudation rates have been major tools for assessment. Assessing the possibility of using naturally occurring chelating agents (e.g. citrate and oxalate) for bioremediation of metals contaminated soils and development and validation of analytical techniques have been additional foci. The results show that from soil-living fungi and ectomycorrhizal roots exudation rates of especially LMWOAs increase significantly at Cd and Pb stress (1-100 μM), while As (as arsenate) and mixtures of metals with As have little effect. The impact of ECM fungi is large and much higher exudation rates are found when the symbionts are present both for controls and metal treatments compared to NM plants. In soil systems there was a significant mobilization of metals from soils under presence of saprotrophic fungi. Both N as well as elevated CO2 (700 ppm) causes sizable increases in exudation rates, independent of biomass, and is a finding that suggests that the availability of easily degradable carbon in soil raises, which may be highly important for the carbon flux in soil. Mycorrhizal seedlings (10 months old) increased total soil respiration ~50% compared to controls without plants in non-sterile soil systems. Key words: amino acids, 13C, carbon cycle, ectomycorrhiza, elevated CO2, exudation, DOC, LMWOA, metal stress, monosaccharides, oxalate, Pinus sylvestris, saprotrophic fungi, soil respiration

  • 222.
    Johansson, Emma M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Fransson, Petra M. A.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    Ekblad, Alf
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Hees, Patrick A. W.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Autotrophic and heterotrophic soil respiration: the effects of non-mycorrhizal and mycorrhizal seedlings under elevated CO2Manuskript (preprint) (Annet vitenskapelig)
  • 223.
    Johansson, Emma M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Fransson, Petra M. A.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    Finlay, Roger D.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    van Hees, Patrick A. W.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Quantitative analysis of exudates from soil-living basidiomycetes in pure culture as a response to lead, cadmium and arsenic stress2008Inngår i: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 40, nr 9, s. 2225-2236Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Six different ectomycorrhizal fungi (Hebeloma velutipes, Piloderma byssinum, Paxillus involutus, Rhizopogonroseolus, Suillus bovinus and Suillus variegatus) and two saprotrophic fungi (Hypholoma fasciculare andHypholoma capnoides) were exposed to metal stress induced by Pb, Cd and As. After pre-growth ina nutrient solution in Petri dishes, metal exposure was performed either in a nutrient rich solution or ina nutrient poor solution for seven days. The fungi were exposed to two different metal concentrations,low and high (Pb: 10 þ 100 mM; Cd: 1 þ 10 mM; As: 1 þ 10 mM). Exudation of low molecular weightorganic compounds (low molecular weight organic acids (LMWOA), amino acids and dissolved monosaccharides),as well as dissolved organic carbon was quantified as a potential response to the metalstress. The main LMWOA identified was oxalate. Oxalate exudation increased significantly in response toboth low and high Pb and Cd concentrations, as well as low As exposure, relative to nutrient controls.Exposure to As and mixtures of metals (Pb þ Cd, Pb þ As) did not result in any significant increase inoxalate production compared to controls. The presence of a carbon source (glucose) in this study islikely to have been important for exudation of organic compounds. For the nutrient rich (þ1mMglucose) metal treatments exposure to Pb and Cd mainly increased exudation of oxalate and total aminoacids. Production of dissolved monosaccharides, as well as DOC, did not increase significantly in responseto metal exposure, irrespective of nutrient conditions. This may be explained by re-absorption ofthe organic compounds by the mycelium or by the fact that metals had no effect on exudation of thesecompounds.

  • 224.
    Johansson, Emma M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Fransson, Petra M. A.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    Finlay, Roger D.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    van Hees, Patrick A. W.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Quantitative analysis of root and ectomycorrhizal exudates as a response to Pb, Cd and As stress2008Inngår i: Plant and Soil, ISSN 0032-079X, E-ISSN 1573-5036, Vol. 313, nr 1-2, s. 39-54Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We examined exudation of low molecular weight (LMW) organic compounds of ectomycorrhizal (ECM) and non-mycorrhizal (NM) seedlings in relation to metals. Scots pine seedlings, either colonized by one of six different ECM fungi or NM, were grown in Petri dishes containing glass beads and liquid growth medium and exposed to elevated concentrations of Pb, Cd and As. Exudation of LMW organic compounds (LMW organic acids (LMWOAs), amino acids and dissolved monosaccharides) and dissolved organic carbon (DOC) was determined qualitatively and quantitatively and exudation rates were calculated. Metals had a significant impact on exudation, especially of oxalate. For Pb and Cd treatments, exudation of oxalate and total LMWOAs generally increased by 15–45% compared to nutrient controls. Production of amino acids, dissolved monosaccharides and DOC was not significantly stimulated by exposure to metals; however, there were non-significant trends towards increased exudation. Finally, exudation generally increased in the presence of mycorrhizal seedlings compared to NM seedlings. The results suggest that ECM fungi may reduce the toxicity of metals to plants through significant increases in the production of organic chelators. Axenic conditions are required to assess the full potential for production of these molecules but their overall significance in soil ecosystems needs to be determined using additional experiments under more ecologically realistic conditions.

  • 225.
    Johansson, Emma M.
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Fransson, Petra M. A.
    Department of Forest Mycology and Pathology, Swedish University of Agricultural Sciences.
    Finlay, Roger D.
    van Hees, Patrick A. W.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Quantitative analysis of soluble exudates produced by ectomycorrhizal roots as a response to ambient and elevated CO22009Inngår i: Soil Biology and Biochemistry, ISSN 0038-0717, E-ISSN 1879-3428, Vol. 41, nr 6, s. 1111-1116Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite its potential impact on soil carbon flow, few studies have attempted to quantify the effects of elevated carbon dioxide (CO2) on production of exudates by mycorrhizal plants. In this study we quantified low molecular weight (LMW) organic compounds exuded by non-mycorrhizal (NM) and ectomycorrhizal (ECM) plants in relation to exposure to elevated CO2. Scots pine seedlings, either colonized by one of eight different ECM fungi or non-mycorrhizal (NM), were exposed to either ambient (350 ppm) or elevated (700 ppm) concentrations of CO2. Exudation of LMW organic acids (LMWOAs), amino acids, dissolved monosaccharides and total dissolved organic carbon (DOC) was determined and exudation rates were calculated per g root and fungal dry mass. CO2 had a significant impact on exudation. Under elevated CO2, exudation of total LMWOAs increased by 120–160%, amino acids by 250%, dissolved monosaccharides by 130–270% and DOC by 180–220% compared to ambient CO2 treatment. Net CO2 assimilation rates increased significantly by 41–47% for seedlings exposed to elevated CO2. Exuded C calculated as a percentage of assimilated CO2 increased by 41–88% in the elevated CO2 treatment compared to ambient CO2 treatment.

  • 226.
    Johansson, Erik
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Automatiserad GUI-testning2009Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I dagens mjukvaruutveckling har testning kommit mer i fokus än tidigare. Tekniken utvecklas konstant, nya standarder utkommer och uppgraderingar släpps i en större grad. Det är i detta sammanhang som testning är av relevans.

    Den här rapporten tar upp grundläggande testningsmetodik med ett fokus på användargränssnittstestning samt en implementation av ett automatiserat GUI-test (Graphical User Interface, användargränssnitt). Implementeringen av testerna utfördes vid Data Engineering, Network Management som är en del av ABB i Västerås. Implementationen var en del av ett projekt där automatiserade GUI-tester skulle utformas.

  • 227.
    Johansson, Fredrik
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Evaluating the performance of TEWA systems2010Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    It is in military engagements the task of the air defense to protect valuable assets such as air bases from being destroyed by hostile aircrafts and missiles. In order to fulfill this mission, the defenders are equipped with sensors and firing units. To infer whether a target is hostile and threatening or not is far from a trivial task. This is dealt with in a threat evaluation process, in which the targets are ranked based upon their estimated level of threat posed to the defended assets. Once the degree of threat has been estimated, the problem of weapon allocation comes into the picture. Given that a number of threatening targets have been identified, the defenders need to decide on whether any firing units shall be allocated to the targets, and if so, which firing unit to engage which target. To complicate matters, the outcomes of such engagements are usually stochastic. Moreover, there are often tight time constraints on how fast the threat evaluation and weapon allocation processes need to be executed. There are already today a large number of threat evaluation and weapon allocation (TEWA) systems in use, i.e. decision support systems aiding military decision makers with the threat evaluation and weapon allocation processes. However, despite the critical role of such systems, it is not clear how to evaluate the performance of the systems and their algorithms. Hence, the work in thesis is focused on the development and evaluation of TEWA systems, and the algorithms for threat evaluation and weapon allocation being part of such systems. A number of algorithms for threat evaluation and static weapon allocation are suggested and implemented, and testbeds for facilitating the evaluation of these are developed. Experimental results show that the use of particle swarm optimization is suitable for real-time target-based weapon allocation in situations involving up to approximately ten targets and ten firing units, while it for larger problem sizes gives better results to make use of an enhanced greedy maximum marginal return algorithm, or a genetic algorithm seeded with the solution returned by the greedy algorithm.

  • 228.
    Johansson, Fredrik
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Falkman, Göran
    Performance evaluation of TEWA systems for improved decision support2009Inngår i: Modeling decisions for artificial intelligence, Berlin: Springer , 2009, Vol. 5861, s. 205-216Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    In air defense situations, decision makers have to protect defended assets through assigning available firing units to threatening targets in real-time. To their help they have decision support systems known as threat evaluation and weapon allocation (TEWA) systems. The problem of performance evaluation of such systems is of great importance, due to their critical role. Despite this research on this problem is close to non-existing. We are discussing the use of survivability and resource usage cost as comparative performance metrics, which can be used for comparing the effectiveness of different system configurations, by using simulations. These metrics have been implemented into a testified, in which we have performed some comparative experiments. Our results show that changes of individual parts of the threat evaluation and weapon allocation system configuration can have a large effect on the effectiveness of the system as a whole, and illustrate how the metrics and the testbed can be used.

  • 229.
    Johansson, Helena
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Jarl, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Teknik för högre draghastighet2010Inngår i: Nordisk trådteknisk förening: årsmötesbok, Hallstahammar: Nordisk trådteknisk förening (NTTF) , 2010, s. 49-55Konferansepaper (Annet vitenskapelig)
    Abstract [sv]

    Arbetet med projektet Teknik för högre draghastighet har inletts med studier av hur kylsystem för dragskivor är konstruerade, några försök att teoretiskt studera värmetransport i gränsytor och FEM simuleringar av temperaturen i dragskivor.

  • 230.
    Johansson, Peter
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Electromagnetic Green's function for layered systems: applications to nanohole interactions in thin metal films2011Inngår i: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 83, nr 19, s. 195408-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We derive expressions for the electromagnetic Green's function for a layered system using a transfer matrix technique. The expressions we arrive at make it possible to study symmetry properties of the Green's function, such as reciprocity symmetry, and the long-range properties of the Green's function which involves plasmon waves as well as boundary waves, also known as Norton waves. We apply the method by calculating the light-scattering cross section off a chain of nanoholes in a thin Au film. The results highlight the importance of nanohole interactions mediated by surface plasmon propagating along the chain of holes.

  • 231.
    Johansson, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Saffiotti, Alessandro
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Navigating by stigmergy: a realization on an RFID floor for minimalistic robots2009Inngår i: IEEE international conference on robotics and automation: ICRA '09, New York, NY: IEEE conference proceedings, 2009, s. 245-252Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Stigmergy is a mechanism that allows the coordination of actions within the same agent or across different agents by means of traces left in the environment. We propose a stigmergetic approach to robot navigation in which a robot sets values in a hexagonal grid of RFID tags buried under the floor. This approach only requires minimal resources on the robot. The RFID floor will eventually contain a distance map that can guide the robot to a given goal (or set of goals) without the use of any localization system. The same map can be used or improved by other robots or by the same robot at later times. We define algorithms for building the RFID-floor map and for navigating on this map, we prove the convergence of the map building algorithm, and we show an empirical validation of our results using a small robot in a domestic environment.

  • 232.
    Julander, Anneli
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Westberg, Håkan
    Engwall, Magnus
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Distribution of brominated flame retardants in different dust fractions in air from an electronics recycling facility2005Inngår i: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 350, nr 1-3, s. 151-160Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Twelve air samples were collected from an electronic recycling facility in Sweden representing three different dust fractions; respirable, total and inhalable dust. Four samples were collected from each fraction. The highest concentration of polybrominated diphenyl ether (PBDE) #209 (ten bromine atoms) was found in the samples from the inhalable dust fraction (ID), which was 10 times higher than for the "total dust" fraction (TD). The concentration ranges were 157.6-208.6; 13.9-16.7; and 2.8-3.3 ng/m3 for inhalable, total and respirable fractions, respectively. The second most abundant PBDE congener was PBDE #183 (seven bromine atoms), followed by the second most abundant substance 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE) in all samples. In addition, decabromodiphenyl ethane (DeBDethane) was tentatively identified in five of the samples. Because of the large differences in air concentrations between the three fractions in ID, TD and RD, it is suggested that the inhalable instead of "total dust" fraction should be used to assess air concentrations, in particular for the larger and higher brominated flame retardants (BFRs).

  • 233.
    Junges, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet.
    Evaluation of techniques for a learning-driven modeling methodology in multiagent simulation2010Inngår i: Multiagent system technologies / [ed] Jürgen Dix, Cees Witteveen, Berlin, Germany: Springer, 2010, s. 185-196Konferansepaper (Fagfellevurdert)
    Abstract [en]

    There have been a number of suggestions for methodologies supporting the development of multiagent simulation models. In this contribution we are introducing a learning-driven methodology that exploits learning techniques for generating suggestions for agent behavior models based on a given environmental model. The output must be human-interpretable. We compare different candidates for learning techniques - classier systems, neural networks and reinforcement learning - concerning their appropriateness for such a modeling methodology.

  • 234.
    Junges, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Evolution for modeling: a genetic programming framework for SeSAm2011Inngår i: GECCO '11: Proceedings of the 13th annual conference companion on Genetic and evolutionary computation, ACM Digital Library, 2011, s. 551-558Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Developing a valid agent-based simulation model is not always straight forward, but involves a lot of prototyping, testing and analyzing until the right low-level behavior is fully specified and calibrated. Our aim is to replace the try and error search of a modeler by adaptive agents which learn a behavior that then can serve as a source of inspiration for the modeler. In this contribution, we suggest to use genetic programming as the learning mechanism. For this aim we developed a genetic programming framework integrated into the visual agent-based modeling and simulation tool SeSAm, providing similar easy-to-use functionality.

  • 235.
    Junges, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Generating inspiration for multi-agent simulation design by Q-Learning2010Inngår i: MALLOW-2010: proceedings of  the multi-agent logics, languages, and organisations federated workshops 2010, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    One major challenge in developing multiagent simulations is to find the appropriate agent design that is able to generate the intended overall phenomenon dynamics, but does not contain unnecessary details. In this paper we suggest to use agent learning for supporting the development of an agent model: the modeler defines the environmental model and the agent interfaces. Using rewards capturing the intended agent behavior, reinforcement learning techniques can be used for learning the rules that are optimally governing the agent behavior. However, for really being useful in a modeling and simulation context, a human modeler must be able to review and understand the outcome of the learning. We propose to use additional forms of learning as post-processing step for supporting the analysis of the learned model. We test our ideas using a simple evacuation simulation scenario.

  • 236.
    Junges, Robert
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Learning Agent Models in SeSAm: (Demonstration)2013Inngår i: / [ed] Ito, Jonker, Gini and Shehory, The International Foundation for Autonomous Agents and Multiagent Systems (IFAAMAS), 2013Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Designing the agent model in a multiagent simulation is a challenging task due to the generative nature of such systems. In this contribution we present an extension to the multiagent simulation platform SeSAm, introducing a learning-based design strategy for building agent behavior models.

  • 237.
    Junges, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Learning convergence and agent behavior interpretation for designing agent-based simulations2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Designing a proper agent behavior for a multiagent simulation is a complex task as it is not obvious how the agents actions, and interactions among them and with their environment, result in an intended macro-phenomenon. To cope with the complexity involved in this challenge, and to achieve the intended overall result, the modeler may benefit from using agent learning techniques. In this contribution we focus on testing different configurations of the interface between the learning algorithm and the simulation scenario. The learned result is post-processed by a decision tree learner, to derive a comprehensible model for the agent behavior.

  • 238.
    Junges, Robert
    et al.
    Örebro universitet, Institutionen för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Learning Tools for Agent-based Modeling and Simulation2013Inngår i: Künstliche Intelligenz, ISSN 0933-1875, E-ISSN 1610-1987, Vol. 27, nr 3, s. 273-280Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this project report, we describe ongoing research on supporting the development of agent-based simulation models. The vision is that the agents themselves should learn their (individual) behavior model, instead of letting a human modeler test which of the many possible agent-level behaviors leads to the correct macro-level observations. To that aim, we integrate a suite of agent learning tools into SeSAm, a fully visual platform for agent-based simulation models. This integration is the focus of this contribution.

  • 239.
    Junges, Robert
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Klügl, Franziska
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Modeling agent behavior through online evolutionary and reinforcement learning2011Inngår i: Federated Conference on Computer Science and Information Systems (FedCSIS), 2011, IEEE, 2011, s. 643-650Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The process of creation and validation of an agentbased simulation model requires the modeler to undergo a number of prototyping, testing, analyzing and re-designing rounds. The aim is to specify and calibrate the proper low level agent behavior that truly produces the intended macro level phenomena. We assume that this development can be supported by agent learning techniques, specially by generating inspiration about behaviors as starting points for the modeler. In this contribution we address this learning-driven modeling task and compare two methods that are producing decision trees: reinforcement learning with a post-processing step for generalization and Genetic Programming.

  • 240.
    Jönsson, Sofie
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Eriksson, Leif A
    Örebro universitet, Akademin för naturvetenskap och teknik.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Multivariate characterisation and quantitative structure-property relationship modelling of nitroaromatic compounds2008Inngår i: Analytica Chimica Acta, ISSN 0003-2670, E-ISSN 1873-4324, Vol. 621, nr 2, s. 155-162Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A multivariate model to characterise nitroaromatics and related compounds based on molecular descriptors was calculated. Descriptors were collected from literature and through empirical, semi-empirical and density functional theory-based calculations. Principal components were used to describe the distribution of the compounds in a multidimensional space. Four components described 76% of the variation in the dataset. PC1 separated the compounds due to molecular weight, PC2 separated the different isomers, PC3 arranged the compounds according to different functional groups such as nitrobenzoic acids, nitrobenzenes, nitrotoluenes and nitroesters and PC4 differentiated the compounds containing chlorine from other compounds. Quantitative structure-property relationship models were calculated using partial least squares (PLS) projection to latent structures to predict gas chromatographic (GC) retention times and the distribution between the water phase and air using solid-phase microextraction (SPME). GC retention time was found to be dependent on the presence of polar amine groups, electronic descriptors including highest occupied molecular orbital, dipole moments and the melting point. The model of GC retention time was good, but the precision was not precise enough for practical use. An important environmental parameter was measured using SPME, the distribution between headspace (air) and the water phase. This parameter was mainly dependent on Henry's law constant, vapour pressure, logP, content of hydroxyl groups and atmospheric OH rate constant. The predictive capacity of the model substantially improved when recalculating a model using these five descriptors only.

  • 241.
    Jönsson, Sofie
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Eriksson, Leif A.
    van Bavel, Bert
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Multivariate characterisation of nitroaromatic compoundsManuskript (preprint) (Annet vitenskapelig)
  • 242.
    Kalaykov, Ivan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ananiev, Anani
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Iliev, Boyko
    Örebro universitet, Akademin för naturvetenskap och teknik.
    SME robotics demand flexible grippers and fixtures2008Inngår i: Proc. 39th Int. Symposium on Robotics, Seoul, Korea, 2008, s. 62-65Konferansepaper (Fagfellevurdert)
  • 243.
    Kalaykov, Ivan
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Ananiev, Anani
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Iliev, Boykov
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Flexible grippers and fixtures2008Konferansepaper (Fagfellevurdert)
  • 244.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engstrand, Lars
    Dept Bacteriol, Swedish Inst Infect Dis Control SMI, Solna, Sweden.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden; Dept Bacteriol, Swedish Inst Infect Dis Control SMI, Solna, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Expression of Helicobacter pylori TonB Protein in Transgenic Arabidopsis thaliana: toward production of vaccine antigens in plants2010Inngår i: Helicobacter, ISSN 1083-4389, E-ISSN 1523-5378, Vol. 15, nr 5, s. 430-437Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The aim of this study was to produce a recombinant version of the highly antigenic Helicobacter pylori TonB (iron-dependent siderophore transporter protein HP1341) in transgenic plants as a candidate oral vaccine antigen. Materials and Methods: Using Agrobacterium-mediated gene transfer, we introduced three different constructs of the tonB gene into the genome of the model plant Arabidopsis thaliana. We investigated transgene insertion by PCR, produced TonB antibodies for analysis of the production of the recombinant protein in plants, verified the identity of the protein produced by mass spectrometry analysis, and analyzed the number of genetic inserts in the plants by Southern blotting. Results: Three different constructs of the expression cassette (full-length tonB, tonB truncated in the 5' end removing the codons for a transmembrane helix, and the latter construct with codons for the endoplasmic reticulum SEKDEL retention signal added to the 3' end) were used to find the most effective way to express the TonB antigen. Production of TonB protein was detected in plants transformed with each of the constructs, confirmed by both Western blotting and mass spectrometry analysis. No considerable differences in protein expression from the three different constructs were observed. The protein concentration in the plants was at least 0.05% of the total soluble proteins. Conclusions: The Helicobacter pylori TonB protein can be produced in Arabidopsis thaliana plants in a form that is recognizable by rabbit anti-TonB antiserum. These TonB-expressing plants are highly suitable for animal studies of oral adminstration as a route for immunization against Helicobacter infections.

  • 245.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Marks, Ellen
    University of Gothenburg, Gothenburg, Sweden.
    Lycke, Nils
    University of Gothenburg, Gothenburg, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Unemo, Magnus
    Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Construction, immunogenicity and protective efficacy in mice of a prototype chimeric Chlamydia trachomatis MOMP vaccine candidate antigen2011Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A chimeric gene construct of Chlamydia trachomatis serovar E major outer membrane protein (MOMP) was designed, and expressed as a candidate vaccine antigen. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP, and successfully expressed and purified in a recombinant Escherichia coli system. BALB/c mice were immunized intranasally with the chimeric MOMP antigen and Cholera toxin (CT) adjuvant, three immunizations with 10 days intervals. A final boost with the identical antigen preparation was given intravaginally. Challenge with live C. trachomatis serovar D was performed 10 days after boost. Antibodies in serum and vaginal washes were determined with the identical chimeric MOMP construct as antigen in ELISAs. All mice in vaccine groups (N=10/group and experiment) developed a strong antigen-specific IgG response in serum, and some also had detectable antigen-specific IgG in vaginal washes. An IgA response, albeit weaker, was detected in some of the mice both in serum and in vaginal washes.

    After challenge with C. trachomatis, 80 and 100% of the mice became infected in two experiments, respectively. However, the vaccinated groups cleared the infection significantly faster than control groups (all vaccinated mice healthy day 24 [90% day 16], compared to day 40 for controls).

    Thus, the new chimeric MOMP antigen construct gave rise to a significant immune response in mice (s-IgG). It also conferred substantial protection to infection caused by genital C. trachomatis infection of a different subtype.

  • 246.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Uppsala universitet, Uppsala, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala universitet, Uppsala, Sweden.
    Andersson, Sören
    Örebro University Hospital, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    A novel chimeric MOMP antigen expressed in Escherichia coli, Arabidopsis thaliana, and Daucus carota as a potential Chlamydia trachomatis vaccine candidate2011Inngår i: Protein Expression and Purification, ISSN 1046-5928, E-ISSN 1096-0279, Vol. 80, nr 2, s. 194-202Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in Escherichia coli and in transgenic plants failed. A chimeric gene construct of C. trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The designed construct was successfully expressed in E. coli, in Arabidopsis thaliana, and in Daucus carota. The chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in both E. coli and in transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP – up to 3% of TSP.

  • 247.
    Kalbina, Irina
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wallin, Anita
    Uppsala universitet, Uppsala, Sweden.
    Lindh, Ingrid
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Engström, Peter
    Uppsala universitet, Uppsala, Sweden.
    Andersson, Sören
    Universitetssjukhuset i Örebro, Örebro, Sweden.
    Strid, Åke
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Expression of chimeric Chlamydia trachomatis MOMP protein antigen in Arabidopsis thaliana and Daucus carota2011Inngår i: Molecular farming: plants as a production platform for high value proteins / [ed] Ann Depicker, Bryssel: COST , 2011, s. 38-38Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Urogenital chlamydial infection, caused by Chlamydia trachomatis, is the main sexually transmitted infection in Sweden. Despite active programmes for detection and case finding, nearly 37 000 cases were reported in 2010. Serovar E strains are considered to cause approximately 40-50% of these cases. A vaccine would be highly valuable in order to control the epidemic.

    The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in transgenic plants failed. A chimeric gene construct of Chlamydia trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The construct was based on known T and B cell epitopes located in the variable segment (VS) 2 and 4 loops of MOMP.

    The designed construct was successfully expressed in Arabidopsis thaliana, and in Daucus carota. A chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in the transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP– up to 3% of TSP.

  • 248.
    Kang, Yu
    et al.
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden; Dept Chem, Zhejiang Univ Hangzhou, Zhejiang, Peoples R China.
    Li, Xin
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden.
    Tu, Yaoquan
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Wang, Qi
    Dept Chem, Zhejiang Univ Hangzhou, Zhejiang, Peoples R China.
    Ågren, Hans
    Sch Biotechnol, Dept Theoret Chem, Royal Inst Technol, Stockholm, Sweden.
    On the mechanism of protein adsorption onto hydroxylated and nonhydroxylated TiO2 surfaces2010Inngår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 114, nr 34, s. 14496-14502Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Protein adsorption onto implant surfaces is of great importance for the regulation of implant bioactivity. Surface modification of implants is a promising way in the molecular design of biocompatible materials against nonspecific adsorption of proteins. On the basis of these fundamental facts, we focus in this work on the different behavior of protein adsorption on hydroxylated and nonhydroxylated rutile TiO2 (110) surfaces through molecular dynamics simulations. Our investigation indicates that the distribution of the water molecules at the interface induced by the surface modification plays an important role in the protein adsorption. The surface with modified hydroxyl groups was observed to have much greater affinity to the protein, as reflected by the larger protein−surface electrostatic interaction and by the larger amount of adsorbed residues. The highly ordered structure of the modified hydroxyl groups on the hydroxylated surface diminishes the possibility of hydrogen bond formation between the surface and the water molecules above it, which in turn makes it easier for the protein to move closer to the surface with hydroxyl modification.

  • 249.
    Karlsson, Alexander
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Evaluating credal set theory as a belief framework in high-level information fusion for automated decision-making2010Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    High-level information fusion is a research field in which methods for achieving an overall understanding of the current situation in an environment of interest are studied. The ultimate goal of these methods is to provide effective decision-support for human or automated decision-making. One of the main proposed ways of achieving this is to reduce the uncertainty, coupled with the decision, by utilizing multiple sources of information. Handling uncertainty in high-level information fusion is performed through a belief framework, and one of the most commonly used such frameworks is based on Bayesian theory. However, Bayesian theory has often been criticized for utilizing a representation of belief and evidence that does not sufficiently express some types of uncertainty. For this reason, a generalization of Bayesian theory has been proposed, denoted as credal set theory, which allows one to represent belief and evidence imprecisely. In this thesis, we explore whether credal set theory  yields measurable advantages, compared to Bayesian theory, when used as a belief framework in high-level information fusion for automated decision-making, i.e., when decisions are made by some pre-determined algorithm. We characterize the Bayesian and credal operators for belief updating and evidence combination and perform three experiments where the Bayesian and credal frameworks are evaluated with respect to automated decision-making. The decision performance of the frameworks are measured by enforcing a single decision, and allowing a set of decisions, based on the frameworks’ belief and evidence structures. We construct anomaly detectors based on the frameworks and evaluate these detectors with respect to maritime surveillance. The main conclusion of the thesis is that although the credal framework uses considerably more expressive structures to represent belief and evidence, compared to the Bayesian framework, the performance of the credal framework can be significantly worse, on average, than that of the Bayesian framework, irrespective of the amount of imprecision.

  • 250.
    Karlsson, Fredrik
    et al.
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Petersson, David
    Örebro universitet, Akademin för naturvetenskap och teknik.
    Examensarbete på Flex Datasystem AB: Säljstödsystem till Flex CRM2009Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    This is the report for the examination of the Sales support system at Flex Datasystem. The project has consisted of building an extension of a web application in Microsoft .NET Framework. The web application is a so called CRM (Customer Relations Manager) –system that is being used internally within the company (Flex Datasystem), named Flex CRM. The application is to be extended with an additional section called Sales Support.

    A sales support is a section of the application targeted the employees on Flex Datasystem with the role of a Sales-person. A sales-persons task assignment consists of dealing with the selling of products developed by Flex Datasystem. The sales support system is to ease their work and management of clients and ongoing contracts.

    This report will go in to detail of what a CRM system is good for and how it can be used, what a sales support system is, who benefits from it and how the approach taken in developing  and implementing it in Flex CRM.

    The report will also talk about what tools used when building this application, how the page structure is structured and the database design. The system is written with the programming language Visual Basic for asp .NET in the design layer and with C# in the Data Access Layer.

2345678 201 - 250 of 613
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf